Oxides 598 OXIDES

Low explosive, lED filler. Black powder weapon propellant Oxidizer Oxidizer Oxidizer Oxidizer... 

Magnox Oxide Oxide Oxide Oxide or metal Magnox or oxide... 

Component Silica Alumina Lime Magnesia oxides oxide oxide... 

In practice, then, the friction between unlubricated metal surfaces should probably be considered that between oxide layer or composite surfaces in which there are oxide-oxide, oxide-metal, and metal-metal components. If one considers only two of the three—metal-metal and oxide-oxide friction— one may estimate surface composition from the frictional force using the relationship... 

Faraday constant formal potential galvanic cell indicator electrode Nemst equation oxidant oxidation oxidizing agent... 

Fuel kernel Carbide Carbide Oxide Carbide Oxide Oxide Oxide... 

Baeyer-Villiger Oxidation- oxidation of ketones to esters and lactones via oxygen insertion... 

Thiazol-2-yl radicals have also been generated by silver oxide oxidation of thiazol-2-ylhydrazine in various aromatic solvents (Scheme 69). The... 

Oxidized starches Oxidizers Oxidizing alkyds Oxidoreductases... 

The scope of oxidation chemistry is enormous and embraces a wide range of reactions and processes. This article provides a brief introduction to the homogeneous free-radical oxidations of paraffinic and alkylaromatic hydrocarbons. Heterogeneous catalysis, biochemical and hiomimetic oxidations, oxidations of unsaturates, anodic oxidations, etc, even if used to illustrate specific points, are arbitrarily outside the purview of this article. There are, even so, many unifying features among these areas. 

Oxidation. Oxidation of hydroxybenzaldehydes can result in the formation of a variety of compounds, depending on the reagents and conditions used. Replacement of the aldehyde function by a hydroxyl group results when 2- or 4-hydroxybenzaldehydes are treated with hydrogen peroxide in acidic (42) or basic (43) media pyrocatechol or hydroquinone are obtained, respectively. 

Chlorination. In some instances, the extraction of a pure metal is more easily achieved from the chloride than from the oxide. Oxide ores and concentrates react at high temperature with chlorine gas to produce volatile chlorides of the metal. This reaction can be used for common nonferrous metals, but it is particularly useful for refractory metals like titanium (see Titanium and titanium alloys) and 2irconium (see Zirconium and zirconium compounds), and for reactive metals like aluminum. 

Oxidation. Oxidation of the -amyl alcohols produces aldehydes, which after continued oxidation can yield acids. This route to aldehydes has httle merit. However, oxidative esterifications with alkah metal hypohaUtes (eg, calcium chlorite, Ca(OCl)2) (49), bromates (eg, sodium bromate, NaBrO )... 

Vehicles. The soHd pigments are dispersed iato the ink vehicle, which consists of a combination of resia, oil, and solvent. The solvent is absorbed by the paper, leaving a partially dry ink film of resia and oil that biads the pigment to the paper. This film then hardens by oxidation. Oxidation of the vehicle is aided by varnish driers, ie, metallic salts. Cobalt driers are considered the most effective (see Driers and metallic soaps). 

Direct Oxidation of Propylene to Propylene Oxide. Comparison of ethylene (qv) and propylene gas-phase oxidation on supported silver and silver—gold catalysts shows propylene oxide formation to be 17 times slower than ethylene oxide (qv) formation and the CO2 formation in the propylene system to be six times faster, accounting for the lower selectivity to propylene oxide than for ethylene oxide. Increasing gold content in the catalyst results in increasing acrolein selectivity (198). In propylene oxidation a polymer forms on the catalyst surface that is oxidized to CO2 (199—201). Studies of propylene oxide oxidation to CO2 on a silver catalyst showed a rate oscillation, presumably owing to polymerization on the catalyst surface upon subsequent oxidation (202). 

Leaded Zinc Oxide. Oxides containing more than 5 wt % basic lead sulfate are classified as leaded and are made ia the American process from high lead materials, usually lead sulfide mineral, or by blending ziac oxide and basic lead sulfate. There is only one manufacturer ia the United States and the product contains 20—28 wt % basic lead sulfate. Leaded oxides are used only ia mbber ia the United States. 

Oxidation. Oxidized or blown castor oils are clear viscous oils that are made by the intimate mixing (blowing) of castor oil and air or oxygen at 80—130°C, with or without the use of a catalyst. The reaction is a combination of oxidation and polymerization promoted by transitionary metals like iron, copper, and manganese (60,61). The range of the properties of commercially available oils are given in Table 8. 

Oxidation. Oxidation reactions utilising supported catalysts usually present extraordinary challenges, because most oxidations are highly exothermic and may generate extremely high localized temperatures that the catalyst surface must survive to have an adequately long service lifetime. In addition, in many cases the desired product is subject to further oxidation, which must be prevented or minimized. 

Oxidation. Oxidation of 1,1,1,2-tetrachloroethane in the presence of ionizing radiation gives dichloroacetyl chloride, Cl CHCOCl (117). The gas-phase photochlorination of 1,1,1,2-tetrachloroethane in the absence and presence of oxygen has been studied (115). 

H1C phosphate orthophosphoric acid (AP+ andZn"+) calcined 2inc oxide, calcined magnesium oxide oxides phosphate luting agent, base... 

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